Microstructure and tensile properties of FeMnNiCuCoSnx high entropy alloys

High-entropy FeMnNiCuCoSnx (x denotes the atomic fraction of Sn) alloys with good plasticity have been developed. The systematical investigation demonstrates that the concentration of Sn element plays a significant role in the microstructure and tensile properties. As 0.03 < x < 0.05, the alloys exhibit high tensile strength and plasticity, and the maximum elongation strain and strength are 16.9% and 476.9 MPa, respectively, because of their single FCC solutions. While the concentration of Sn is higher than 0.05, an intermetallic compound (Cu5.6Sn) in the interdendritic regions forms, which degrades the ductility of alloys.